The effects of certain psychotherapeutic drugs on pre- and post-synaptic development of the muscarinic acetylcholine system will be studied utilizing cell culture of fetal rat brain and mouse neuroblastoma cells. Experiments are proposed to define (1) any interrelationships between pre- and post-synaptic elements during development; and (2) any effects of certain psychotherapeutic drugs (antipychotics and anti-depressants) on these elements during development and during the "mature" state. With fetal rat brain cells pre-synaptic development of the muscarinic acetylcholine system will be studied by following the development of the enzyme that synthesizes acetylcholine; while post-synaptic development will be studied by determining the development of (1) receptors for acetylcholine (muscarinic) by radioactive ligand-binding assays and (2) neurotransmitter-stimulated levels in intracellular cyclic GMP. With mouse neuroblastoma cells, the muscarinic acetylcholine receptor will be studied by physico-chemical (ligand binding assay), biochemical-pharmacological (cyclic GMP formation) and electrophysiological (acetylcholine changes in membrane potential) techniques. By studying this receptor after chronic treatment with certain psychotherapeutic drugs, drug induced alterations in this receptor may be determined.